Insulator.



J. HARRIS.

msuu'ron. APPLICATION FILED B20116, 1912.

A Patented Nov. '18, 1913,

' WITNESSES:

4 INVENTOR.

JOHN B. Ill i318, OF GRAFTON, PENNSYLVANIA.

INSULATOB.

Specification of Le'tterslatent.

Patented Nov. 18, 1913.

Application filed December 18, 1912. Serial No. 736,975.

To all whom it may concern:

Be it known that I, JOHN R. HARRIS, a citizen of the United States, and residing in the borough of Grafton. in the county of Allegheny and State of Pennsylvania, have invented or discovered new and useful Improvements in Insulators, of which the following is a specification.

My invention consists of a new and useful improvement. in split insulators or two-part electrical wiring knobs. I

Split insulators are preferred for wiring but their use is attended by numerous disadvantages. The bases and caps are shipped together in bulk and must be sorted out and matched before use. In installing, the base, cap and wire are held together against the Wall or other support while the nail is inserted and driv'en home. The loss through breakage and spalling in shipment, and the loss of time and inconvenience Lin sorting and installing are very great.

In my present invention the base and cap are'connected together by a tube of tough, not easily broken material inserted in the nail bores of the said base and cap and whose ends are upset to prevent withdrawal. Sutlieient looseness is provided so that the base and cap may be separated sufliciently to introduce the wire and when the base and cap are driven snugly together to clamp the ;wire, as when nailed to the wall, the excess length of the tube is accommodated in the .eountersunk portion of the base. The insulator is secured in plane by means of a nail Mf gerew inserted through the tube.

Iirthe accompanyingdrawings, Figure 1 is a longitudinal section of one of my insulators installed; Fig. 2 is a similar view of the insulator with the base and cap extended; Fig. 3 is an end elevation of the insulator. looking downwardly in Fig. 2; Fig. 4 is an elevation of the interlocking tube. and Fig. 5 is .a'perspeetive of the insulatorwitl the base and cap snugly together.

The following is a detailed desrription of the drawings:

A and B are respectively, the base and cap of a split insulator. The particular design of these elements is not important as my invention may be applied to anysplit insulator having an axial nail bore.

In the base A, 1 is the axial nail bore ending in the usual countersinking 2, and 3 is the axial nail bore of the cap B.

C is a tube, which may be of metal but is preferably of fiber or other insulating ma.- terial, inserted through the bores ,/1.' and 3 and having its ends upset outwardly to prevent accidental withdrawal. As shown in Fig: 1-, said tube C is of greater length than the'oomhined length of bores land 3. so that when the base i l and rap B abut together to clamp the wire l). the excess length of tube C extends into the oountersinking 2 of base A. This permits the cap to be raised'or separated somewhat from the base. as in Fig. 2, to permit the insertion of the wire D.

In installingt'lm insulator, the wire D is laid in the usual clamping groove 4 and a nail or screw E inserted through the tube C and driven into the wall or other support F. the head of the nail and of the tube seating in the usual countersunk outer end of the bore 3' of the cap B. It is thus/evident that the bases and caps may be matched and the interlocking tubes installed at the factory or by'dealers. thus saving much time and labor and avoiding the breakage and spoiling which attends shipment inloose bulk. The

't-ubes being of substantial material are not plied to dealers for assembling insulators in I JOHN HARRIS;

Vvitnes ses I E. A. LAURENCE,

,W. S. WALSH. 

